Re: [PATCH 1/2] mm: add locked parameter to get_user_pages_remote()

From: Michal Hocko
Date: Thu Oct 27 2016 - 11:20:20 EST


On Thu 27-10-16 12:55:27, Michal Hocko wrote:
> On Thu 27-10-16 10:51:40, Lorenzo Stoakes wrote:
> > This patch adds a int *locked parameter to get_user_pages_remote() to allow
> > VM_FAULT_RETRY faulting behaviour similar to get_user_pages_[un]locked().
> >
> > Taking into account the previous adjustments to get_user_pages*() functions
> > allowing for the passing of gup_flags, we are now in a position where
> > __get_user_pages_unlocked() need only be exported for his ability to allow
> > VM_FAULT_RETRY behaviour, this adjustment allows us to subsequently unexport
> > __get_user_pages_unlocked() as well as allowing for future flexibility in the
> > use of get_user_pages_remote().
>
> I would also add that this shouldn't introduce any functional change.

Forgot to mention that this also opens doors to change other g_u_p_r
callers to allow FAULT_RETRY logic.

--
Michal Hocko
SUSE Labs